Thread: For loop Driver Testing

I am testing a nextDate() and prevDate() methods which increment a SimpleDate object and for testing purposes I am running it 400 times with a for loop. For both tests the for loop is the same but
I can only get it to increment once then print that 400 times. I figure this is a simple fix but I just can't figure it out. Any help is appreciated, thank you.

// Test nextDate
      SimpleDate dateTest = new SimpleDate(12 , 31 , 2008);
      for(int i = 0; i <400; i++) {
    	  System.out.println(dateTest.nextDate()); 
      }

nextDate() just returns a SimpleDate object that is one day later and changed the month or year depending on the day.

Where is the code for SimpleDate class? And also you are not storing the new Date value in the object so, how it would come to know the nextDate() for which Date? It only has already stored value and always keep getting the nextDate() according to that Date.